Process for controlling the temperature of a dyeing mixture

ABSTRACT

A process and apparatus is disclosed which is used in dyeing textiles. The dye liquor has less than 10 percent water in perchlorethylene along with a dye and an emulsifier to keep the water emulsified in the perchlorethylene. The dye liquor is heated to cause the mixture to boil and the vapors are condensed. The condensed vapors are directed away from the dye liquor until a desired temperature is reached, at which point they are directed back to the dye liquor to prevent a further temperature increase.

United States Patent 1 [111 3,765,840 Durr et al.v Oct. 16, 1973 1 PROCESS FOR CONTROLLING THE 87-90, 9598, Mar. 11, 1970.

TEMPERATURE OF A DYEING MIXTURE Inventors: Larry L. Durr, Indianapolis; Byron Jan Clay, Brownsburg, both of Ind.

Assignee: Textile Technology, Inc., San Diego,

Calif.

Filed: May 20, 1971 Appl. No.: 145,396

U.S. Cl 8/175, 8/94, 8/158 Int. Cl D06p 1/68 Field of Search 8/175, 158, 94, 172

References Cited UNITED STATES PATENTS 11/1971 Burger 8/142 3,330,015 7/1967 Sieber 26/19 3,473,175 10/1969 Sieber 8/158 FOREIGN PATENTS OR APPLICATIONS 6,710,789 3/1968 Netherlands 8/174 1,103,860 9/1965 Great Britain 8/174 OTHER PUBLICATIONS I Milicevic, Solvent Dyeing; Theory & Practice", pp.

W. A. S. White, Amer. Dyestuff Reporter, July 31, 1967, pp. 18-24.

R. Q. Brewster, Organic Chemistry, 2nd Ed. 1953, pp. 1 18-120.

Ciba-Geigy Review, 1971/4, pp. 11-13.

Primary Examiner-Leon D. Rosdol Assistant ExaminerT. J. Herbert, Jr. Attorney-Woodard, Weikart, Emhardt & Naughton [5 7] ABSTRACT A process and apparatus is disclosed which is used in dyeing textiles. The dye liquor has less than 10 per- 10 Claims, 2 Drawing Figures COOL ANT SOURCE ll COOLANT RETURN 1'! /l(n CONDENSER I 30 12 STEAM r 1 SOURCE T :1? STEAM STORAGE v RETURN VALVE 21 CONTROL 22 O PATENTEDBCI 16 1973 TEMPERATURE C Ill /1@ iii STEAM SOU RC E V II? STEAM RETURN CONTROL 100 00fib15o04b50i0f00 /0 H2O m1 c 0 L INVENTORS ARRY L. Dune. g BY BYZQN JAM CLAY MEDAMA JMZM MTG AT TORN EYS PROCESS FOR CONTROLLING THE TEMPERATURE OF A DYEING MIXTURE BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to textile treating processes and apparatus which use two or more liquids in a treatment mixture. It also relates to processes and apparatus for the control of temperature of textile treating mixtures.

2. Description of the Prior Art Typically in the prior art, the temperature of textile treatment liquids has been controlled by controlling the amount of steam fed to a heat exchanger through which the liquids are circulated. Thermostatic type controls are often used to sense the temperature of the liquids and to automatically control the steam flow. Electric heating systems coupled to thermostatic controls are sometimes used to maintain a temperature.

It is important in obtaining uniform dyeing of textiles, that all portions of the textiles and dyeing liquor be the same temperature. Certain fabrics, such as acrylics, accept a dye when a specific temperature is reached and it is important that the temperature be brought up slowly and uniformly to obtain .uniform dyeing. Difficulties in maintaining uniform temperatures through the dye liquor and in controlling the rate of rise of the temperature can cause uneven and spotty dyeing. Special care must be taken to insure that all portions of the textile are at the same temperature.

The use of mixtures of perchlorethylene and water or trichlorethylene and water is disclosed in US. Pat. Nos. 3,330,015, 3,370,330, and 3,473,175 to J.H. Sieber. None of these mixtures are used at temperatures near or at the azeotropic boiling point of the mixtures, thus reaction rates are moderately slow.

SUMMARY OF THE INVENTION This invention relates to subjecting textiles to a treating mixture containing two or-more liquids, heating the mixture to obtain rapid vaporization of the liquid, condensing the resulting vapors and directing at least a portion of the condensate away from the treating mixture until the temperature of the dyeing mixture increases to a desired level.

By proper choice of liquids and by keeping the mixture boiling, an extremely uniform and well controlled temperature achieved in the perchlorethylene and water system, among others, is dependent principally upon the ratio of the two liquids and is not significantly affected by the amount of heat applied to cause the liquid to boil. Even if a large amount of heat is applied in one area, the result will be'primarily an increase in the rate of conversion from liquid to vapor and not significantly an increase in temperature in that area.

The invention permits the use at atmospheric pressure of water and perchlorethylene mixtures at temperatures in excess of 87.7 C. This is important because several textile treatment procedures require tempera tures in excess of 87.7C to operate efficiently, and treatment mixtures containing perchlorethylene and water can produce superior textiles- BRIEF DESCRIPTION OF THE DRAWING FIG. 1 illustrates textile treating apparatus embodying the invention.

FIG. 2 is a graph indicating with a solid line the manner in which the boiling point of a mixture of water and perchlorethylene varies depending upon the relative amounts of each and indicating with a dotted line the composition of the vapors at the various temperatures.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring in particular to FIG. 1 there is illustrated a container 10 which has within it a rotating textile receiving basket 11 of the type conventionally used in dry cleaning machines. Within the container 10 is a textile treating mixture 12 and within the basket 11 are textiles 30 to be treated. The treating mixture 12 is circulated and heated by a mill pump 14 and a steam heated heat exchanger 13.

Vapors from the heated mixture 12 can pass through a vapor outlet 15 to a water cooled condenser 16. A vent 17 in the condenser 16 assures that atmospheric pressure will always be maintained within container 10. The condensate from the condenser 16 passes from the condenser outlet 18 to two valves 19 and 20. The two valves are controlled by the valve control 21 in such a manner that when one of the valves is open the other is closed. The valve control 21 is essentially a thermostat or the equivalent thereof and of conventional design. It has a temperature sensing probe 22 to permit response to the temperature of the textile treating mixture 12. Valve 19 is opened when the textile treating mixture is below the desired temperature and valve 20 is opened when the desired temperature is reached. A storage tank 23 stores the condensate which is produced while valve 19 is open.

It is important for effective operation of the apparatus illustrated in FIG. 1 that the solvents chosen be related to the temperature desired to be obtained. Azeotrope forming mixtures are preferred. Those mixtures which form azeotropes will have a boiling point which is different than the boiling point of either of the two liquids of which it is formed. The boiling point will depend upon the ratio of the two liquids.

Perchlorethylene and water are azeotrope-forming liquids. The graph of FIG. 2 illustrates witha solid line the manner in which the boiling point of a mixture of perchlorethylene and water varies dependent upon the percentage of water in a perchlorethylene and water mixture. Line ab represents the boiling point of a one phase liquid containing a small percentage of perchlorethylene in water. Line bc represents the boiling point of a two phase liquid, one phase containing mostly perchlorethylene and the other mostly water. Line cd represents the boiling point of a one phase liquid containing a small percentage of water in perchlorethylene. Water boils at C, and a mixture of perchlorethylene and water having from about 99 to about 6 percent by weight of water boils at 87.7 C. The vapor at 87.7C contains 15.8 percent by weight of water (point e The dotted line'of the graph illustrates an approximate condensation curve for the vapors.

It can be observed from line cd of FIG. 2 that any temperature from 87.7 to 121 C can be obtained in a boiling mixture and the temperature is dependent upon the percentage of water in the perchlorethylene. Vapors from a boiling mixture of perchlorethylene and water having less than 15.8 percent water will have a higher concentration of water than will the mixture from which the vapors came. Thus by boiling the mixture having less than 15.8 percent water and allowing the vapors to escape, the concentration of water in the mixture will decrease. When the water concentration decreases to about 6 percent, the boiling point will begin to rise and will continue to rise from 87.7 to 121 C as the water concentration decreases further, eventually to zero at 121 C. If it is desired to remain at any temperature within that range, all that has to be done is to condense the vapors from the boiling mixture and return them to the mixture. This willkeep the water concentration constant and will thus prevent an increase in the boiling point.

it can be noted that the boiling point of such a mixture is thus continuously variable over a fairly broad range. The specific heat of perchlorethylene is 0.21 cal./g/ C and of water is l cal./g/ C. if a mixture of these two liquids is not at the boiling point, heat transferred from a'heat exchanger to a textile in the mixture must be transferred by an increase in temperature of the mixture. However, if the mixture is at the boiling point, heat can be transferred primarily by a change in phase not involving a temperature change. The latent heat of evaporation for perchlorethylene is 50.1 cal/g. and for water it is 545.1 cal/g. Thus it is much easier to maintain a uniform temperature in a mixture which is boiling than in a mixture which is not boiling.

This characteristic of a mixture having a boiling point different than the boiling point of the liquids from which the mixture was made is not limited to perchlorethylene and water mixtures, but rather it is characteristic of all azeotrope forming liquids. Both trichloroethylene and 1,1,l-trichloroethane form azeotropes with water and are conventionally used in the textile industry. Aside from the improved regulation of temperature which such mixtures can provide, such mixtures have the advantage of providing both water and a nonaqueous solvent for reactions at a high temperature with the textile. Water acts as a plasticizer for synthetic fibers and causes swelling of cellulosic fibers which aids in dyeing. Water also acts as a solvent for many textile treating materials, typically those which have polar molecules such as acid dyes. The solvent can wet textiles much more rapidly than water, it requires less heat to reach a specific temperature and it acts as a solvent for many textile treating materials, typically those which'have essentially non-polar molecules such as disperse dyes. The high temperatures will cause rapid reaction rates.

Because dyeing technology is geared for dyeing from water systems, the ability to use a solvent mixture which boils at essentially the boiling point of water and which in fact contains water, allows prior art chemicals and procedures to beused with little or no change in many instances. Because among other reasons solvents can wet fabrics much more rapidly than water, dyeing times are much shorter with a large amount of solvent. Because perchlorethyiene does not weaken synthetic fibers, such as polyester, as do most other solvents, and because it can produce a controlled boiling point at 100C, it is the preferred solvent. Preferably less than 5 percent but greater than 0.5 percent water is used with the perchlorethylene. it is clear that while the boiling point of water will vary with atmospheric pressure, the boiling produced by this invention can be made to be 100C at any atmospheric pressure whether at high elevations or below sea level.

It is apparent from the preceeding description that if the proper amount (less than 5 percent) of water is initially added to perchlorethylene and the condensate continually directed back to the treating mixture, the

temperature can easily be maintained at a resulting 9710lC boiling point, (the preferred treatment temperature range of many dyeing processes.) While this does not prevent a rapid and uneven rise in temperature to the boiling point, it does eliminate the need for thermostatically controlled valves. In dyeing, the preferred ranges of ingredients of the treating mixture when the desired temperature is above 92C and the process is carried out under atmospheric pressure are:

from 0.8 to 4.0 percent water from to 98 percent perchlorethylene from 0.05 to 8 percent of an emulsifying agent from 0.05 to 10 percent of a dye.

EXAMPLE 1 In a textile treating apparatus of the aforedescribed type (FIG. 1), 1,200 grams of woven 100 percent nylon 66 fabric was subjected to a treating mixture of 19 liters of perchlorethylene, 500 ml. of water, 5 grams of an acid dye, Eriosin Scarlet 4R Supra dye made by Geigy Chemical Company Ardsley, N.Y., 20 ml. of a slightly cationic carrier and softener, Laureltex DAV made by Laurel Products Corp. Philadelphia, Pa., and 50 ml. of a solution of a detergent, Staticol made by RR. Streets, Inc., Chicago, lll. The mill pump circulated this treating mixture, originally at 25 C, through a steam heated heat exchanger; and the temperature of the mixture increased about l0 C per minute until the mixture began to boil. As in all examples, the basket containing the textiles was rotated during the preceding steps.

Vapors from the boiling mixture were condensed in a condenser and directed away from the boiling mixture until a temperature of 98 C was reached. The rate of rise of temperature was about 08C per minute while the condensate was being directed away. When a temperature of 98C was reached, the condensate was directed back to the mixture and the temperature remained at 98C for 4 minutes. At the end of that time the steam to the heat exchanger was turned off and the mixture drained from the apparatus. The fabric was then rinsed with 19 liters of perchlorethylene for 2 minutes and dried with 50 to 55C air for 10 minutes.

The dyed fabric was a moderately deep red color, evenly dyed. It had very good light fastness, wash fastness, cracking and abrasion test results.

EXAMPLE 2 In a textile treating apparatus of the aforedescribed type (FIGJ), 900 grams of a 100 percent polyester fabric was subjected to a treating mixture of 19 liters of perchlorethylene, 600 ml. of water, 5g. of a disperse dye, Resolin Dark Blue Bl made by Verona, Union,

NJ. and 100 ml. of an emulsifier, T anatex DS-l4. The mill purn circulated this treating mixture, originally at 25C, through a steam heated heat exchanger; and the temperature of the mixture increased about 10C per minute until the mixture began to boil.

Vapors from the boiling mixture were condensed in a condenser and directed away from the boiling mixture until a temperature of 98C was reached. The rate of rise of temperature was about 0.8C per minute while the condensate was being directed away. When a temperature of 99C was reached, the condensate was directed back to the mixture and the temperature remained at 99C for 20 minutes. At the end of that time the steam to the heat exchanger was turned off and the mixture drained from the apparatus. The fabric was rinsed with 19 liters of perchlorethylene for 3 minutes and dried with 50 to 55 C air for minutes.

Excellent evenly dyed results were obtained.

EXAMPLE 3 In a textile treating apparatus of the aforedescribed type (FlG.l), 800 grams of an acrylic fabric was subjected to a treating mixture containing 32 grams of a basic dye Astrazon Blue B liquid made by Verona, 400 ml. water, 18 l. trichlorethylene, and 130 ml. of an emulsifier, Tanatex DS-l4 made by Tanatex Chemical Corp., Lyndhurst, NJ. The mill pump circulated this treating mixture, originally at 25C, through a steam heated heat exchanger, and the temperature of the mixture increased about 10C per minute until the mixture began to boil.

Vapors from the boiling mixture were condensed and directed away from the mixture until a temperature of 80C was reached. The rate of rise of remperature was about 0.8C per minute while the condensate was being directed away. When a temperature of 80C was reached the condensate was directed back to the mixture and the temperature remained at 80C for 5 minutes. At the end of that time the steam to the heat exchanger was turned off and the mixture drained from the apparatus. The fabric was rinsed with 19 liters of trichlorethylene for 3 minutes and dried with 50 to 55C air for 10 minutes.

Excellent even dyed results were obtained.

EXAMPLE 4 In a textile treating apparatus of the aforedescribed type (FlG.l) and with the valve control 21 adjusted so that valve is always open, 1,200 grams of a nylon fabric was subjected to a treating mixture containing 19 liters of perchlorethylene, 250 ml. of water, 5 grams of an acid dye, Eriosin Scarlet 4R Supra, and 50 ml. of a detergent, Staticol. The mill pump circulated this treating mixture, originally at C, through a steam heated heat exchanger, and the temperature of the mixture increased about 1C per minute until the mixture began to boil at 98C. The temperature stabilized at 99and remained there for 6 minutes. The fabric was rinsed as in the preceeding examples and the results of the dyeing were very good. However, variations in humidity, moisture content of the fabric, and residual moisture within the system make it difiicult to consistently obtain a given temperature.

1 claim:

1. A process for controlling the temperature of a dyeing mixture under atmospheric pressure which comprises:

a. subjecting textiles to be dyed to a dyeing mixture containing two or more liquids and a dye under atmospheric pressure,

b. heating the mixture, to which the textiles are being subjected, to obtain rapid vaporization of the liquid as well as heating of the textiles,

c. condensing the vapors from the heated dyeing mixture with a condenser to form a condensate, and

d. directing at least a portion of the condensate away from the dyeing mixture until the temperature of the dyeing mixture subsequently increases to a desired level.

2. The process of claim 1 which additionally comprises the subsequent step of e. directing all of the condensate coming from said condenser after the desired temperature has been reached back into the dyeing mixture to prevent a further temperature increase.

3. The process of claim 1 in which one of the liquids is water and another of the liquids is a halogenated hydrocarbon.

' 4. The process of claim 3 in which the halogenated hydrocarbon is perchlorethylene and the water is presentin an amount less than 5 percent by weight.

5. The process of claim 1 in which two of the liquids of the dyeing mixture form an azeotrope with each other.

6. The process of claim 1 in which two of the liquids of the dyeing mixture are immiscible with each other.

7. A process for controlling the temperature of a dyeing mixture under atmospheric pressure which contains water and perchlorethylene which comprises:

a. subjecting textiles to be dyed under atmospheric pressure to a dyeing mixture containing perchlorethylene, a dye and less than 5 percent by weight of water, the amount of water being the amount required to give the mixture after reaching equilibrium a boiling point which is the temperature desired for dyeing the textiles,

b. heating the mixture, to which the textiles are being subjected, to the boiling point,

c. condensing the vapors from the heated dyeing mixture with a condenser to form a condensate, and

d. returning the condensate to the dyeing mixture to prevent any further rise in the boiling point of the dyeing mixture.

8. The process of claim 7 in which the amount of water in the dyeing mixture will cause the mixture to boil at a temperature from 97 to 101 C while the condensate is being returned to the dyeing mixture.

9. A process for dyeing textiles which comprises:

a. subjecting the textiles to a dyeing mixture containing by weight:

from about 0.8 to 4.0 percent water,

from to 98 percent of perchlorethylene,

from 0.05 to 8 percent of an emulsifying agent, and

from 0.05 to 10 percent of a dye at a temperature above C and under atmospheric pressure.

10. The process of claim 9 in which the textile is polyester'and said dye is a disperse dye.

l i t t 

2. The process of claim 1 which additionally comprises the subsequent step of e. directing all of the condensate coming from said condenser after the desired temperature has been reached back into the dyeing mixture to prevent a further temperature increase.
 3. The process of claim 1 in which one of the liquids is water and another of the liquids is a halogenated hydrocarbon.
 4. The process of claim 3 in which the halogenated hydrocarbon is perchlorethylene and the water is present in an amount less than 5 percent by weight.
 5. The process of claim 1 in which two of the liquids of the dyeing mixture form an azeotrope with each other.
 6. The process of claim 1 in which two of the liquids of the dyeing mixture are immiscible with each other.
 7. A process for controlling the temperature of a dyeing mixture under atmospheric pressure which contains water and perchlorethylene which compriseS: a. subjecting textiles to be dyed under atmospheric pressure to a dyeing mixture containing perchlorethylene, a dye and less than 5 percent by weight of water, the amount of water being the amount required to give the mixture after reaching equilibrium a boiling point which is the temperature desired for dyeing the textiles, b. heating the mixture, to which the textiles are being subjected, to the boiling point, c. condensing the vapors from the heated dyeing mixture with a condenser to form a condensate, and d. returning the condensate to the dyeing mixture to prevent any further rise in the boiling point of the dyeing mixture.
 8. The process of claim 7 in which the amount of water in the dyeing mixture will cause the mixture to boil at a temperature from 97* to 101* C while the condensate is being returned to the dyeing mixture.
 9. A process for dyeing textiles which comprises: a. subjecting the textiles to a dyeing mixture containing by weight: from about 0.8 to 4.0 percent water, from 70 to 98 percent of perchlorethylene, from 0.05 to 8 percent of an emulsifying agent, and from 0.05 to 10 percent of a dye at a temperature above 90* C and under atmospheric pressure.
 10. The process of claim 9 in which the textile is polyester and said dye is a disperse dye. 